Apparatus for and method of processing substrate subjected to exposure process

ABSTRACT

A substrate subjected to an exposure process by an exposure unit is transported into a cleaning processing unit in a substrate processing apparatus. An adjustment is made to the presence time (more specifically, the waiting time or the cleaning time) of the exposed substrate in the cleaning processing unit to adjust the instant of the end of a cleaning process so as to provide a constant time interval between the instant of the completion of the exposure process and the instant of the end of the cleaning process. Such adjustments provide a constant time interval between the instant of the completion of the exposure process and the instant of the start of a post-exposure bake process, and also provide a constant time interval between the, instant of the completion of the cleaning process and the instant of the start of the post-exposure bake process. This achieves further improvements in the line width uniformity of a pattern formed when a chemically amplified resist is used.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method of processing a substrate suchas a semiconductor substrate subjected to an exposure process, a glasssubstrate for a liquid crystal display device, a glass substrate for aphotomask, a substrate for an optical disk and the like, and a substrateprocessing apparatus for executing the method.

2. Description of the Background Art

As is well known, semiconductor and liquid crystal display products andthe like are fabricated by performing a series of processes includingcleaning, resist coating, exposure, development, etching, interlayerinsulation film formation, heat treatment, dicing and the like on theabove-mentioned substrate. An apparatus which performs a resist coatingprocess on a substrate to transfer the substrate to an exposure unit andwhich receives an exposed substrate from the exposure unit to perform adevelopment process on the exposed substrate, among the above-mentionedprocesses, is widely used as a so-called coater-and-developer.

The exposure unit (also known as a stepper) for performing an exposureprocess is typically connected to and provided in juxtaposition with theabove-mentioned coater-and-developer, and prints a circuit pattern on asubstrate formed with a resist film. With recent decrease in width oflines exposed to light, a lamp for use in printing of a pattern in suchan exposure unit is shifting from a conventional ultraviolet lightsource toward a KrF excimer laser light source and also toward an ArFexcimer laser light source. A chemically amplified resist is used when apattern is printed using a KrF light source and an ArF light source. Thechemically amplified resist is a photoresist of the type such that anacid formed by a photochemical reaction during the exposure process actsas a catalyst for resist reactions such as crosslinking, polymerizationand the like in the subsequent heat treatment step to change thesolubility of the resist in a developing solution, whereby patternprinting is completed.

When the chemically amplified resist is used, a slight variation inprocessing conditions exerts a large influence upon line widthuniformity because an extremely small amount of acid catalyst is formedduring the exposure process. In particular, it is known that the timeinterval between the instant of the end of the exposure process and theinstant of the start of a post-exposure bake process exerts the greatestinfluence on the line width uniformity. Thus, a technique forcontrolling the time interval between the end of the exposure processand the start of the post-exposure bake process to be constant isproposed, for example, in Japanese Patent Application Laid-Open No.2002-43208 and Japanese Patent Application Laid-Open No. 2004-342654.Such a technique can improve the line width uniformity when thechemically amplified resist is used.

Unfortunately, some variations in line width still occur even if thetime interval between the end of the exposure process and the start ofthe post-exposure bake process is made constant. In particular, asubstrate subjected to an immersion exposure process is subjected to adeionized water cleaning process in the coater-and-developer. In such acase, it is contemplated that the time interval between the instant atwhich the deionized water cleaning process is completed and the instantat which the post-exposure bake process is executed is also important.However, no particular consideration has conventionally been given tocontrolling this time interval.

SUMMARY OF THE INVENTION

The present invention is intended for a substrate processing apparatusdisposed adjacent to an exposure apparatus.

According to the present invention, the substrate processing apparatuscomprises: a cleaning processing part for performing at least a cleaningprocess on a substrate subjected to an exposure process by the exposureapparatus; a heating processing part for performing a heating process ona substrate subjected to the cleaning process; a transport mechanism forreceiving a substrate from the exposure apparatus to transport thesubstrate through the cleaning processing part to the heating processingpart; and a controller for providing an approximately constant firstinterprocess time interval between the instant at which the exposureapparatus completes the exposure process of a substrate and the instantat which the heating processing part starts the heating process of thesubstrate, and for providing an approximately constant secondinterprocess time interval between the instant at which the cleaningprocessing part completes the cleaning process of the substrate and theinstant at which the heating processing part starts the heating processof the substrate.

This provides a uniform processing history for the substrates, therebyfurther improving the line width uniformity of a pattern.

Preferably, the controller adjusts the instant at which the cleaningprocessing part completes the cleaning process to thereby provide theapproximately constant first interprocess time interval and theapproximately constant second interprocess time interval.

This provides a uniform processing history for the substrates easilywith reliability.

The present invention is also intended for a method of processing asubstrate subjected to an exposure process.

It is therefore an object of the present invention to provide anapparatus for and a method of processing a substrate which are capableof further improving the line width uniformity of a pattern.

These and other objects, features, aspects and advantages of the presentinvention will become more apparent from the following detaileddescription of the present invention when taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a substrate processing apparatus according tothe present invention;

FIG. 2 is a front view of a liquid processing part;

FIG. 3 is a front view of a thermal processing part;

FIG. 4 is a view showing a construction around substrate rest parts;

FIG. 5A is a plan view of a transport robot;

FIG. 5B is a front view of the transport robot;

FIG. 6 is a view for illustrating a construction of a cleaningprocessing unit;

FIG. 7A is a side sectional view of a heating part with a temporarysubstrate rest part;

FIG. 7B is a plan view of the heating part with the temporary substraterest part;

FIG. 8 is a side view of an interface block;

FIG. 9 is a block diagram schematically showing a control mechanism;

FIG. 10 is a flow chart showing a processing procedure from the end ofexposure in an exposure unit to the start of a post-exposure bakeprocess in a heating part; and

FIG. 11 is a timing chart for processing from the end of the exposure tothe post-exposure bake process.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A preferred embodiment according to the present invention will now bedescribed in detail with reference to the drawings.

FIG. 1 is a plan view of a substrate processing apparatus according tothe present invention. FIG. 2 is a front view of a liquid processingpart in the substrate processing apparatus. FIG. 3 is a front view of athermal processing part in the substrate processing apparatus. FIG. 4 isa view showing a construction around substrate rest parts. An XYZrectangular coordinate system in which an XY plane is defined as thehorizontal plane and a Z axis is defined to extend in the verticaldirection is additionally shown in FIG. 1 and the subsequent figures forpurposes of clarifying the directional relationship therebetween.

The substrate processing apparatus according to the preferred embodimentis an apparatus (a so-called coater-and-developer) for forming ananti-reflective film and a photoresist film on substrates such assemiconductor wafers by coating and for performing a development processon substrates subjected to a pattern exposure process. The substrates tobe processed by the substrate processing apparatus according to thepresent invention are not limited to semiconductor wafers, but mayinclude glass substrates for a liquid crystal display device, and thelike.

The substrate processing apparatus according to the preferred embodimentincludes an indexer block 1, a BARC (Bottom Anti-Reflective Coating)block 2, a resist coating block 3, a development processing block 4, andan interface block 5. In the substrate processing apparatus, the fiveprocessing blocks 1 to 5 are arranged in side-by-side relation. Anexposure unit (or stepper) EXP which is an external apparatus separatefrom the substrate processing apparatus according to the presentinvention is provided and connected to the interface block 5. That is,the substrate processing apparatus according to the preferred embodimentis disposed adjacent to the exposure unit EXP. The substrate processingapparatus according to the preferred embodiment and the exposure unitEXP are connected via LAN lines (not shown) to a host computer 100.

The indexer block 1 is a processing block for transferring unprocessedsubstrates received from the outside of the substrate processingapparatus outwardly to the BARC block 2 and the resist coating block 3,and for transporting processed substrates received from the developmentprocessing block 4 to the outside of the substrate processing apparatus.The indexer block 1 includes a table 11 for placing thereon a pluralityof (in this preferred embodiment, four) cassettes (or carriers) C injuxtaposition, and a substrate transfer mechanism 12 for taking anunprocessed substrate W out of each of the cassettes C and for storing aprocessed substrate W into each of the cassettes C. The substratetransfer mechanism 12 includes a movable base 12 a movable horizontally(in the Y direction) along the table 11, and a holding arm 12 b mountedon the movable base 12 a and for holding a substrate W in a horizontalposition. The holding arm 12 b is capable of moving upwardly anddownwardly (in the Z direction) over the movable base 12 a, pivotingwithin a horizontal plane and moving back and forth in the direction ofthe pivot radius. Thus, the substrate transfer mechanism 12 can causethe holding arm 12 b to gain access to each of the cassettes C, therebytaking an unprocessed substrate W out of each cassette C and storing aprocessed substrate W into each cassette C. The cassettes C may be ofthe following types: an SMIF (standard mechanical interface) pod, and anOC (open cassette) which exposes stored substrates W to the atmosphere,in addition to a FOUP (front opening unified pod) which storessubstrates W in an enclosed or sealed space.

The BARC block 2 is provided in adjacent relation to the indexer block1. A partition 13 for closing off the communication of atmosphere isprovided between the indexer block 1 and the BARC block 2. The partition13 is provided with a pair of vertically arranged substrate rest partsPASS1 and PASS2 each for placing a substrate W thereon for the transferof the substrate W between the indexer block 1 and the BARC block 2.

The upper substrate rest part PASS1 is used for the transport of asubstrate W from the indexer block 1 to the BARC block 2. The substraterest part PASS1 includes three support pins. The substrate transfermechanism 12 of the indexer block 1 places an unprocessed substrate Wtaken out of one of the cassettes C onto the three support pins of thesubstrate rest part PASS1. A transport robot TR1 of the BARC block 2 tobe described later receives the substrate W placed on the substrate restpart PASS1. The lower substrate rest part PASS2, on the other hand, isused for the transport of a substrate W from the BARC block 2 to theindexer block 1. The substrate rest part PASS2 also includes threesupport pins. The transport robot TR1 of the BARC block 2 places aprocessed substrate W onto the three support pins of the substrate restpart PASS2. The substrate transfer mechanism 12 receives the substrate Wplaced on the substrate rest part PASS2 and stores the substrate W intoone of the cassettes C. Pairs of substrate rest parts PASS3 to PASS10 tobe described later are similar in construction to the pair of substraterest parts PASS1 and PASS2.

The substrate rest parts PASS1 and PASS2 extend through the partition13. Each of the substrate rest parts PASS1 and PASS2 includes an opticalsensor (not shown) for detecting the presence or absence of a substrateW thereon. Based on a detection signal from each of the sensors, ajudgment is made as to whether or not the substrate transfer mechanism12 and the transport robot TR1 of the BARC block 2 stand ready totransfer and receive a substrate W to and from the substrate rest partsPASS1 and PASS2.

Next, the BARC block 2 will be described. The BARC block 2 is aprocessing block for forming an anti-reflective film by coating at thebottom of a photoresist film (i.e., as an undercoating film for thephotoresist film) to reduce standing waves or halation occurring duringexposure. The BARC block 2 includes a bottom coating processor BRC forcoating the surface of a substrate W with the anti-reflective film, apair of thermal processing towers 21 for performing a thermal processwhich accompanies the formation of the anti-reflective film by coating,and the transport robot TR1 for transferring and receiving a substrate Wto and from the bottom coating processor BRC and the pair of thermalprocessing towers 21.

In the BARC block 2, the bottom coating processor BRC and the pair ofthermal processing towers 21 are arranged on opposite sides of thetransport robot TR1. Specifically, the bottom coating processor BRC ison the front side of the substrate processing apparatus, and the pair ofthermal processing towers 21 are on the rear side thereof. Additionally,a thermal barrier not shown is provided on the front side of the pair ofthermal processing towers 21. Thus, the thermal effect of the pair ofthermal processing towers 21 upon the bottom coating processor BRC isavoided by spacing the bottom coating processor BRC apart from the pairof thermal processing towers 21 and by providing the thermal barrier.

As shown in FIG. 2, the bottom coating processor BRC includes threecoating processing units BRC1, BRC2 and BRC3 similar in construction toeach other and arranged in stacked relation in bottom-to-top order. Thethree coating processing units BRC1, BRC2 and BRC3 are collectivelyreferred to as the bottom coating processor BRC, unless otherwiseidentified. Each of the coating processing units BRC1, BRC2 and BRC3includes a spin chuck 22 for rotating a substrate W in a substantiallyhorizontal plane while holding the substrate W in a substantiallyhorizontal position under suction, a coating nozzle 23 for applying acoating solution for the anti-reflective film onto the substrate W heldon the spin chuck 22, a spin motor (not shown) for rotatably driving thespin chuck 22, a cup (not shown) surrounding the substrate W held on thespin chuck 22, and the like.

As shown in FIG. 3, one of the thermal processing towers 21 which iscloser to the indexer block 1 includes six hot plates HP1 to HP6 forheating a substrate W up to a predetermined temperature, and cool platesCP1 to CP3 for cooling a heated substrate W down to a predeterminedtemperature and maintaining the substrate W at the predeterminedtemperature. The cool plates CP1 to CP3 and the hot plates HP1 to HP6are arranged in stacked relation in bottom-to-top order in this thermalprocessing tower 21. The other of the thermal processing towers 21 whichis farther from the indexer block 1 includes three adhesion promotionprocessing parts AHL1 to AHL3 arranged in stacked relation inbottom-to-top order for thermally processing a substrate W in a vaporatmosphere of HMDS (hexamethyl disilazane) to promote the adhesion ofthe resist film to the substrate W. The locations indicated by the crossmarks (x) in FIG. 3 are occupied by a piping and wiring section orreserved as empty space for future addition of processing units.

Thus, stacking the coating processing units BRC1 to BRC3 and the thermalprocessing units (the hot plates HP1 to HP6, the cool plates CP1 to CP3,and the adhesion promotion processing parts AHL1 to AHL3 in the BARCblock 2) in tiers provides smaller space occupied by the substrateprocessing apparatus to reduce the footprint thereof. The side-by-sidearrangement of the pair of thermal processing towers 21 is advantageousin facilitating the maintenance of the thermal processing units and ineliminating the need for extension of ducting and power supply equipmentnecessary for the thermal processing units to a much higher position.

FIGS. 5A and 5B are views for illustrating the transport robot TR1provided in the BARC block 2. FIG. 5A is a plan view of the transportrobot TR1, and FIG. 5B is a front view of the transport robot TR1. Thetransport robot TR1 includes a pair of (upper and lower) holding arms 6a and 6 b in proximity to each other for holding a substrate W in asubstantially horizontal position. Each of the holding arms 6 a and 6 bincludes a distal end portion of a substantially C-shaped planconfiguration, and a plurality of pins 7 projecting inwardly from theinside of the substantially C-shaped distal end portion for supportingthe peripheral edge of a substrate W from below.

The transport robot TR1 further includes a base 8 fixedly mounted on anapparatus base (or an apparatus frame). A guide shaft 9 c is mountedupright on the base 8, and a threaded shaft 9 a is rotatably mounted andsupported upright on the base 8. A motor 9 b for rotatably driving thethreaded shaft 9 a is fixedly mounted to the base 8. A lift 10 a is inthreaded engagement with the threaded shaft 9 a, and is freely slidablerelative to the guide shaft 9 c. With such an arrangement, the motor 9 brotatably drives the threaded shaft 9 a, whereby the lift 10 a is guidedby the guide shaft 9 c to move up and down in a vertical direction (inthe Z direction).

An arm base 10 b is mounted on the lift 10 a pivotably about a verticalaxis. The lift 10 a contains a motor 10 c for pivotably driving the armbase 10 b. The pair of (upper and lower) holding arms 6 a and 6 bdescribed above are provided on the arm base 10 b. Each of the holdingarms 6 a and 6 b is independently movable back and forth in a horizontaldirection (in the direction of the pivot radius of the arm base 10 b) bya sliding drive mechanism (not shown) mounted to the arm base 10 b.

With such an arrangement, the transport robot TR1 is capable of causingeach of the pair of holding arms 6 a and 6 b to independently gainaccess to the substrate rest parts PASS1 and PASS2, the thermalprocessing units provided in the thermal processing towers 21, thecoating processing units provided in the bottom coating processor BRC,and the substrate rest parts PASS3 and PASS4 to be described later,thereby transferring and receiving substrates W to and from theabove-mentioned parts and units, as shown in FIG. 5A.

Next, the resist coating block 3 will be described. The resist coatingblock 3 is provided so as to be sandwiched between the BARC block 2 andthe development processing block 4. A partition 25 for closing off thecommunication of atmosphere is also provided between the resist coatingblock 3 and the BARC block 2. The partition 25 is provided with the pairof vertically arranged substrate rest parts PASS3 and PASS4 each forplacing a substrate W thereon for the transfer of the substrate Wbetween the BARC block 2 and the resist coating block 3. The substraterest parts PASS3 and PASS4 are similar in construction to theabove-mentioned substrate rest parts PASS1 and PASS2.

The upper substrate rest part PASS3 is used for the transport of asubstrate W from the BARC block 2 to the resist coating block 3.Specifically, a transport robot TR2 of the resist coating block 3receives the substrate W placed on the substrate rest part PASS3 by thetransport robot TR1 of the BARC block 2. The lower substrate rest partPASS4, on the other hand, is used for the transport of a substrate Wfrom the resist coating block 3 to the BARC block 2. Specifically, thetransport robot TR1 of the BARC block 2 receives the substrate W placedon the substrate rest part PASS4 by the transport robot TR2 of theresist coating block 3.

The substrate rest parts PASS3 and PASS4 extend through the partition25. Each of the substrate rest parts PASS3 and PASS4 includes an opticalsensor (not shown) for detecting the presence or absence of a substrateW thereon. Based on a detection signal from each of the sensors, ajudgment is made as to whether or not the transport robots TR1 and TR2stand ready to transfer and receive a substrate W to and from thesubstrate rest parts PASS3 and PASS4. A pair of (upper and lower) coolplates WCP of a water-cooled type for roughly cooling a substrate W areprovided under the substrate rest parts PASS3 and PASS4, and extendthrough the partition 25 (See FIG. 4).

The resist coating block 3 is a processing block for applying a resistonto a substrate W coated with the anti-reflective film by the BARCblock 2 to form a resist film. In this preferred embodiment, achemically amplified resist is used as the photoresist. The resistcoating block 3 includes a resist coating processor SC for forming theresist film by coating on the anti-reflective film serving as theundercoating film, a pair of thermal processing towers 31 for performinga thermal process which accompanies the resist coating process, and thetransport robot TR2 for transferring and receiving a substrate W to andfrom the resist coating processor SC and the pair of thermal processingtowers 31.

In the resist coating block 3, the resist coating processor SC and thepair of thermal processing towers 31 are arranged on opposite sides ofthe transport robot TR2. Specifically, the resist coating processor SCis on the front side of the substrate processing apparatus, and the pairof thermal processing towers 31 are on the rear side thereof.Additionally, a thermal barrier not shown is provided on the front sideof the pair of thermal processing towers 31. Thus, the thermal effect ofthe pair of thermal processing towers 31 upon the resist coatingprocessor SC is avoided by spacing the resist coating processor SC apartfrom the pair of thermal processing towers 31 and by providing thethermal barrier.

As shown in FIG. 2, the resist coating processor SC includes threecoating processing units SC1, SC2 and SC3 similar in construction toeach other and arranged in stacked relation in bottom-to-top order. Thethree coating processing units SC1, SC2 and SC3 are collectivelyreferred to as the resist coating processor SC, unless otherwiseidentified. Each of the coating processing units SC1, SC2 and SC3includes a spin chuck 32 for rotating a substrate W in a substantiallyhorizontal plane while holding the substrate W in a substantiallyhorizontal position under suction, a coating nozzle 33 for applying aresist solution onto the substrate W held on the spin chuck 32, a spinmotor (not shown) for rotatably driving the spin chuck 32, a cup (notshown) surrounding the substrate W held on the spin chuck 32, and thelike.

As shown in FIG. 3, one of the thermal processing towers 31 which iscloser to the indexer block 1 includes six heating parts PHP1 to PHP6arranged in stacked relation in bottom-to-top order for heating asubstrate W up to a predetermined temperature. The other of the thermalprocessing towers 31 which is farther from the indexer block 1 includescool plates CP4 to CP9 arranged in stacked relation in bottom-to-toporder for cooling a heated substrate W down to a predeterminedtemperature and maintaining the substrate W at the predeterminedtemperature.

Each of the heating parts PHP1 to PHP6 is a thermal processing unitincluding, in addition to an ordinary hot plate for heating a substrateW placed thereon, a temporary substrate rest part for placing asubstrate W in an upper position spaced apart from the hot plate, and alocal transport mechanism 34 (See FIG. 1) for transporting a substrate Wbetween the hot plate and the temporary substrate rest part. The localtransport mechanism 34 is capable of moving up and down and moving backand forth, and includes a mechanism for cooling down a substrate W beingtransported by circulating cooling water therein.

The local transport mechanism 34 is provided on the opposite side of theabove-mentioned hot plate and the temporary substrate rest part from thetransport robot TR2, that is, on the rear side of the substrateprocessing apparatus. The temporary substrate rest part has both an openside facing the transport robot TR2 and an open side facing the localtransport mechanism 34. The hot plate, on the other hand, has only anopen side facing the local transport mechanism 34, and a closed sidefacing the transport robot TR2. Thus, both of the transport robot TR2and the local transport mechanism 34 can gain access to the temporarysubstrate rest part, but only the local transport mechanism 34 can gainaccess to the hot plate. The heating parts PHP1 to PHP6 are generallysimilar in construction (FIGS. 7A and 7B) to heating parts PHP7 to PHP12in the development processing block 4 to be described later.

A substrate W is transported into each of the above-mentioned heatingparts PHP1 to PHP6 having such a construction in a manner to bedescribed below. First, the transport robot TR2 places a substrate Wonto the temporary substrate rest part. Subsequently, the localtransport mechanism 34 receives the substrate W from the temporarysubstrate rest part to transport the substrate W to the hot plate. Thehot plate performs a heating process on the substrate W. The localtransport mechanism 34 takes out the substrate W subjected to theheating process by the hot plate, and transports the substrate W to thetemporary substrate rest part. During the transport, the substrate W iscooled down by the cooling function of the local transport mechanism 34.Thereafter, the transport robot TR2 takes out the substrate W subjectedto the heating process and transported to the temporary substrate restpart.

In this manner, the transport robot TR2 transfers and receives thesubstrate W to and from only the temporary substrate rest part held atroom temperature in each of the heating parts PHP1 to PHP6, but does nottransfer and receive the substrate W directly to and from the hot plate.This avoids the temperature rise of the transport robot TR2. The hotplate having only the open side facing the local transport mechanism 34prevents the heat atmosphere leaking out of the hot plate from affectingthe transport robot TR2 and the resist coating processor SC. Thetransport robot TR2 transfers and receives a substrate W directly to andfrom the cool plates CP4 to CP9.

The transport robot TR2 is precisely identical in construction with thetransport robot TR1. Thus, the transport robot TR2 is capable of causingeach of a pair of holding arms thereof to independently gain access tothe substrate rest parts PASS3 and PASS4, the thermal processing unitsprovided in the thermal processing towers 31, the coating processingunits provided in the resist coating processor SC, and the substraterest parts PASS5 and PASS6 to be described later, thereby transferringand receiving substrates W to and from the above-mentioned parts andunits.

Next, the development processing block 4 will be described. Thedevelopment processing block 4 is provided so as to be sandwichedbetween the resist coating block 3 and the interface block 5. Apartition 35 for closing off the communication of atmosphere is alsoprovided between the resist coating block 3 and the developmentprocessing block 4. The partition 35 is provided with the pair ofvertically arranged substrate rest parts PASS5 and PASS6 each forplacing a substrate W thereon for the transfer of the substrate Wbetween the resist coating block 3 and the development processing block4. The substrate rest parts PASS5 and PASS6 are similar in constructionto the above-mentioned substrate rest parts PASS1 and PASS2.

The upper substrate rest part PASS5 is used for the transport of asubstrate W from the resist coating block 3 to the developmentprocessing block 4. Specifically, a transport robot TR3 of thedevelopment processing block 4 receives the substrate W placed on thesubstrate rest part PASS5 by the transport robot TR2 of the resistcoating block 3. The lower substrate rest part PASS6, on the other hand,is used for the transport of a substrate W from the developmentprocessing block 4 to the resist coating block 3. Specifically, thetransport robot TR2 of the resist coating block 3 receives the substrateW placed on the substrate rest part PASS6 by the transport robot TR3 ofthe development processing block 4.

The substrate rest parts PASS5 and PASS6 extend through the partition35. Each of the substrate rest parts PASS5 and PASS6 includes an opticalsensor (not shown) for detecting the presence or absence of a substrateW thereon. Based on a detection signal from each of the sensors, ajudgment is made as to whether or not the transport robots TR2 and TR3stand ready to transfer and receive a substrate W to and from thesubstrate rest parts PASS5 and PASS6. A pair of (upper and lower) coolplates WCP of a water-cooled type for roughly cooling a substrate W areprovided under the substrate rest parts PASS5 and PASS6, and extendthrough the partition 35 (See FIG. 4).

The development processing block 4 is a processing block for performinga development process on a substrate W subjected to an exposure process.The development processing block 4 is also capable of cleaning anddrying a substrate W subjected to an immersion exposure process. Thedevelopment processing block 4 includes a development processor SD forapplying a developing solution onto a substrate W exposed in a patternto perform the development process, a cleaning processor SOAK forperforming a cleaning process and a drying process on a substrate Wsubjected to the immersion exposure process, a pair of thermalprocessing towers 41 and 42 for performing a thermal process whichaccompanies the development process, and the transport robot TR3 fortransferring and receiving a substrate W to and from the developmentprocessor SD, the cleaning processor SOAK and the pair of thermalprocessing towers 41 and 42. The transport robot TR3 is preciselyidentical in construction with the above-mentioned transport robots TR1and TR2.

As shown in FIG. 2, the development processor SD includes fourdevelopment processing units SD1, SD2, SD3 and SD4 similar inconstruction to each other and arranged in stacked relation inbottom-to-top order. The four development processing units SD1 to SD4are collectively referred to as the development processor SD, unlessotherwise identified. Each of the development processing units SD1 toSD4 includes a spin chuck 43 for rotating a substrate W in asubstantially horizontal plane while holding the substrate W in asubstantially horizontal position under suction, a nozzle 44 forapplying the developing solution onto the substrate W held on the spinchuck 43, a spin motor (not shown) for rotatably driving the spin chuck43, a cup (not shown) surrounding the substrate W held on the spin chuck43, and the like.

The cleaning processor SOAK includes a single cleaning processing unitSOAK1. As shown in FIG. 2, the cleaning processing unit SOAK1 isdisposed under the development processing unit SD1. FIG. 6 is a view forillustrating the construction of the cleaning processing unit SOAK1. Thecleaning processing unit SOAK1 includes a spin chuck 421 for rotating asubstrate W about a vertical rotation axis passing through the center ofthe substrate W while holding the substrate W in a horizontal position.

The spin chuck 421 is fixed on the upper end of a rotary shaft 425rotated by an electric motor not shown. The spin chuck 421 is formedwith a suction passage (not shown). With the substrate W placed on thespin chuck 421, exhausting air from the suction passage allows the lowersurface of the substrate W to be vacuum-held on the spin chuck 421,whereby the substrate W is held in a horizontal position.

A first pivoting motor 460 is provided on one side of the spin chuck421. A first pivoting shaft 461 is connected to the first pivoting motor460. A first arm 462 is coupled to the first pivoting shaft 461 so as toextend in a horizontal direction, and a cleaning processing nozzle 450is provided on a distal end of the first arm 462. The first pivotingmotor 460 drives the first pivoting shaft 461 to rotate, and drives thefirst arm 462 to pivot, whereby the cleaning processing nozzle 450 movesto over the substrate W held by the spin chuck 421.

A tip of a cleaning supply pipe 463 is connected in communication withthe cleaning processing nozzle 450. The cleaning supply pipe 463 isconnected in communication with a cleaning liquid supply source R1 and arinsing liquid supply source R2 through a valve Va and a valve Vb,respectively. Controlling the opening and closing of the valves Va andVb allows the selection of a processing liquid to be supplied to thecleaning supply pipe 463 and the adjustment of the amount of supplythereof. Specifically, a cleaning liquid is supplied to the cleaningsupply pipe 463 by opening the valve Va, and a rinsing liquid issupplied to the cleaning supply pipe 463 by opening the valve Vb.

The cleaning liquid supplied from the cleaning liquid supply source R1or the rinsing liquid supplied from the rinsing liquid supply source R2is fed through the cleaning supply pipe 463 to the cleaning processingnozzle 450. This provides the cleaning liquid or the rinsing liquid fromthe cleaning processing nozzle 450 to the surface of the substrate W.Examples of the cleaning liquid used herein include deionized water, asolution of a complex (ionized) in deionized water, and a fluorine-basedchemical solution. Examples of the rinsing liquid used herein includedeionized water, carbonated water, hydrogen-dissolved water,electrolytic ionized water, and HFE (hydrofluoroether). A two-fluidnozzle which mixes droplets into a gas to eject the mixture may be usedas the cleaning processing nozzle 450.

A second pivoting motor 470 is provided on a different side of the spinchuck 421 than the above-mentioned side. A second pivoting shaft 471 isconnected to the second pivoting motor 470. A second arm 472 is coupledto the second pivoting shaft 471 so as to extend in a horizontaldirection, and a drying processing nozzle 451 is provided on a distalend of the second arm 472. The second pivoting motor 470 drives thesecond pivoting shaft 471 to rotate, and drives the second arm 472 topivot, whereby the drying processing nozzle 451 moves to over thesubstrate W held by the spin chuck 421.

A tip of a drying supply pipe 473 is connected in communication with thedrying processing nozzle 451. The drying supply pipe 473 is connected incommunication with an inert gas supply source R3 through a valve Vc.Controlling the opening and closing of the valve Vc allows theadjustment of the amount of inert gas to be supplied to the dryingsupply pipe 473.

The inert gas supplied from the inert gas supply source R3 is fedthrough the drying supply pipe 473 to the drying processing nozzle 451.This provides the inert gas from the drying processing nozzle 451 to thesurface of the substrate W. Examples of the inert gas used hereininclude nitrogen gas (N₂) and argon gas (Ar).

When supplying the cleaning liquid or the rinsing liquid to the surfaceof the substrate W, the cleaning processing nozzle 450 is positionedover the substrate W held by the spin chuck 421 whereas the dryingprocessing nozzle 451 is retracted to a predetermined position. Whensupplying the inert gas to the surface of the substrate W, on the otherhand, the drying processing nozzle 451 is positioned over the substrateW held by the spin chuck 421 whereas the cleaning processing nozzle 450is retracted to a predetermined position, as shown in FIG. 6.

The substrate W held by the spin chuck 421 is surrounded by a processingcup 423. A cylindrical partition wall 433 is provided inside theprocessing cup 423. A drainage space 431 for draining the processingliquid (the cleaning liquid or the rinsing liquid) used for theprocessing of the substrate W is formed inside the partition wall 433 soas to surround the spin chuck 421. A collected liquid space 432 forcollecting the processing liquid used for the processing of thesubstrate W is formed between the outer wall of the processing cup 423and the partition wall 433 so as to surround the drainage space 431.

A drainage pipe 434 for introducing the processing liquid to a drainageprocessing apparatus (not shown) is connected to the drainage space 431,and a collection pipe 435 for introducing the processing liquid to acollection processing apparatus (not shown) is connected to thecollected liquid space 432.

A splash guard 424 for preventing the processing liquid from thesubstrate W from splashing outwardly is provided over the processing cup423. The splash guard 424 has a configuration rotationally symmetricwith respect to the rotary shaft 425. A drainage guide groove 441 of adog-legged sectional configuration is formed annularly in the innersurface of an upper end portion of the splash guard 424. A collectedliquid guide portion 442 defined by an outwardly downwardly inclinedsurface is formed in the inner surface of a lower end portion of thesplash guard 424. A partition wall receiving groove 443 for receivingthe partition wall 433 in the processing cup 423 is formed near theupper end of the collected liquid guide portion 442.

The splash guard 424 is driven to move upwardly and downwardly in avertical direction by a guard driving mechanism (not shown) including aball screw mechanism and the like. The guard driving mechanism moves thesplash guard 424 upwardly and downwardly between a collection positionin which the collected liquid guide portion 442 surrounds the edgeportion of the substrate W held by the spin chuck 421 and a drainageposition in which the drainage guide groove 441 surrounds the edgeportion of the substrate W held by the spin chuck 421. When the splashguard 424 is in the collection position (or the position shown in FIG.6), the processing liquid splashed from the edge portion of thesubstrate W is guided by the collected liquid guide portion 442 into thecollected liquid space 432, and is then collected through the collectionpipe 435. When the splash guard 424 is in the drainage position, on theother hand, the processing liquid splashed from the edge portion of thesubstrate W is guided by the drainage guide groove 441 into the drainagespace 431, and is then drained through the drainage pipe 434. In thismanner, the drainage and collection of the processing liquid can beselectively carried out.

Referring again to FIG. 3, the thermal processing tower 41 which iscloser to the indexer block 1 includes five hot plates HP7 to HP11 forheating a substrate W up to a predetermined temperature, and cool platesCP10 to CP13 for cooling a heated substrate W down to a predeterminedtemperature and for maintaining the substrate W at the predeterminedtemperature. The cool plates CP10 to CP13 and the hot plates HP7 to HP11are arranged in stacked relation in bottom-to-top order in this thermalprocessing tower 41.

The thermal processing tower 42 which is farther from the indexer block1, on the other hand, includes the six heating parts PHP7 to PHP12 and acool plate CP14 which are arranged in stacked relation. Like theabove-mentioned heating parts PHP1 to PHP6, each of the heating partsPHP7 to PHP12 is a thermal processing unit including a temporarysubstrate rest part and a local transport mechanism.

FIGS. 7A and 7B schematically show the construction of the heating partPHP7 with the temporary substrate rest part. FIG. 7A is a side sectionalview of the heating part PHP7, and FIG. 7B is a plan view of the heatingpart PHP7. Although the heating part PHP7 is shown in FIGS. 7A and 7B,the heating parts PHP8 to PHP12 are precisely identical in constructionwith the heating part PHP7. The heating part PHP7 includes a heatingplate 710 for performing a heating process on a substrate W placedthereon, a temporary substrate rest part 719 for placing a substrate Win an upper or lower position (in this preferred embodiment, an upperposition) spaced apart from the heating plate 710, and a local transportmechanism 720 specific to a thermal processing part for transporting asubstrate W between the heating plate 710 and the temporary substraterest part 719. The heating plate 710 is provided with a plurality ofmovable support pins 721 extendable out of and retractable into theplate surface. A vertically movable top cover 722 for covering asubstrate W during the heating process is provided over the heatingplate 710. The temporary substrate rest part 719 is provided with aplurality of fixed support pins 723 for supporting a substrate W.

The local transport mechanism 720 includes a holding plate 724 forholding a substrate W in a substantially horizontal position. Theholding plate 724 is moved upwardly and downwardly by a screw feed drivemechanism 725, and is moved back and forth by a belt drive mechanism726. The holding plate 724 is provided with a plurality of slits 724 aso as not to interfere with the movable support pins 721 and the fixedsupport pins 723 when the holding plate 724 moves to over the heatingplate 710 and moves into the temporary substrate rest part 719.

The local transport mechanism 720 further includes a cooling element forcooling a substrate W in the course of the transport of the substrate Wfrom the heating plate 710 to the temporary substrate rest part 719. Asillustrated in FIG. 7B, the cooling element may be constructed so that acooling water passage 724 b through which a cooling water flows isprovided inside the holding plate 724. The cooling element may beconstructed so that, for example, a Peltier device or the like isprovided inside the holding plate 724.

The above-mentioned local transport mechanism 720 is provided at therear of (i.e., on the (+Y) side relative to) the heating plate 710 andthe temporary substrate rest part 719 in the apparatus. A transportrobot TR4 of the interface block 5 is disposed on the (+X) side relativeto the heating plate 710 and the temporary substrate rest part 719, andthe transport robot TR3 of the development processing block 4 isdisposed on the (−Y) side relative to the heating plate 710 and thetemporary substrate rest part 719. In an upper portion of an enclosure727 covering the heating plate 710 and the temporary substrate rest part719, i.e., a portion of the enclosure 727 which covers the temporarysubstrate rest part 719, an opening 719 a for allowing the transportrobot TR4 to enter the temporary substrate rest part 719 is provided onthe (+X) side thereof, and an opening 719 b for allowing the localtransport mechanism 720 to enter the temporary substrate rest part 719is provided on the (+Y) side thereof. In a lower portion of theenclosure 727, i.e., a portion of the enclosure 727 which covers theheating plate 710, the (+X) and (−Y) sides thereof (i.e., the surfacesof the enclosure 727 opposed to the transport robot TR3 and thetransport robot TR4) are provided with no openings, and an opening 719 cfor allowing the local transport mechanism 720 to enter the heatingplate 710 is provided on the (+Y) side thereof.

A substrate W is carried into and out of the above-mentioned heatingpart PHP7 in a manner to be described below. First, the transport robotTR4 of the interface block 5 holds an exposed substrate W, and placesthe substrate W onto the fixed support pins 723 of the temporarysubstrate rest part 719. Subsequently, the holding plate 724 of thelocal transport mechanism 720 moves to under the substrate W, and thenmoves slightly upwardly to receive the substrate W from the fixedsupport pins 723. The holding plate 724 which holds the substrate Wmoves backwardly out of the enclosure 727, and moves downwardly to aposition opposed to the heating plate 710. At this time, the movablesupport pins 721 of the heating plate 710 are in a lowered position, andthe top cover 722 is in a raised position. The holding plate 724 whichholds the substrate W moves to over the heating plate 710. After themovable support pins 721 move upwardly and receive the substrate W in areceiving position, the holding plate 724 moves backwardly out of theenclosure 727. Subsequently, the movable support pins 721 movedownwardly to place the substrate W onto the heating plate 710, and thetop cover 722 moves downwardly to cover the substrate W. In this state,the substrate W is subjected to the heating process. After the heatingprocess, the top cover 722 moves upwardly, and the movable support pins721 move upwardly to lift the substrate W. Next, after the holding plate724 moves to under the substrate W, the movable support pins 721 movedownwardly to transfer the substrate W to the holding plate 724. Theholding plate 724 which holds the substrate W moves backwardly out ofthe enclosure 727, and then moves upwardly to transport the substrate Wto the temporary substrate rest part 719. In the course of thetransport, the substrate W supported by the holding plate 724 is cooledby the cooling element of the holding plate 724. The holding plate 724brings the substrate W cooled (to approximately room temperature) ontothe fixed support pins 723 of the temporary substrate rest part 719. Thetransport robot TR4 takes out and transports the substrate W.

The transport robot TR4 transfers and receives the substrate W to andfrom only the temporary substrate rest part 719, but does not transferand receive the substrate W to and from the heating plate 710. Thisavoids the temperature rise of the transport robot TR4. Additionally,the opening 719 c through which the substrate W is placed onto andremoved from the heating plate 710 is formed only on the side of thelocal transport mechanism 720. This prevents the heat atmosphere leakingout through the opening 719 c from raising the temperatures of thetransport robot TR3 and the transport robot TR4 and also from affectingthe development processor SD and the cleaning processor SOAK.

As described above, the transport robot TR4 of the interface block 5 cangain access to the heating parts PHP7 to PHP12 and the cool plate CP14,but the transport robot TR3 of the development processing block 4 cannotgain access thereto. The transport robot TR3 of the developmentprocessing block 4 gains access to the thermal processing unitsincorporated in the thermal processing tower 41.

The pair of vertically arranged substrate rest parts PASS7 and PASS8 inproximity to each other for the transfer of a substrate W between thedevelopment processing block 4 and the interface block 5 adjacentthereto are incorporated in the topmost tier of the thermal processingtower 42. The upper substrate rest part PASS7 is used for the transportof a substrate W from the development processing block 4 to theinterface block 5. Specifically, the transport robot TR4 of theinterface block 5 receives the substrate W placed on the substrate restpart PASS7 by the transport robot TR3 of the development processingblock 4. The lower substrate rest part PASS8, on the other hand, is usedfor the transport of a substrate W from the interface block 5 to thedevelopment processing block 4. Specifically, the transport robot TR3 ofthe development processing block 4 receives the substrate W placed onthe substrate rest part PASS8 by the transport robot TR4 of theinterface block 5. Each of the substrate rest parts PASS7 and PASS8includes both an open side facing the transport robot TR3 of thedevelopment processing block 4 and an open side facing the transportrobot TR4 of the interface block 5.

Next, the interface block 5 will be described. The interface block 5 isa block provided adjacent to the development processing block 4. Theinterface block 5 receives a substrate W with the resist film formedthereon by the resist coating process from the resist coating block 3 totransfer the substrate W to the exposure unit EXP which is an externalapparatus separate from the substrate processing apparatus according tothe present invention. Also, the interface block 5 receives an exposedsubstrate W from the exposure unit EXP to transfer the exposed substrateW to the development processing block 4. The interface block 5 in thispreferred embodiment includes a transport mechanism 55 for transferringand receiving a substrate W to and from the exposure unit EXP, a pair ofedge exposure units EEW1 and EEW2 for exposing the periphery of asubstrate W formed with the resist film, and the transport robot TR4 fortransferring and receiving a substrate W to and from the heating partsPHP7 to PHP12 and cool plate CP14 provided in the development processingblock 4 and the edge exposure units EEW1 and EEW2.

As shown in FIG. 2, each of the edge exposure units EEW1 and EEW2(collectively referred to as an edge exposure part EEW, unless otherwiseidentified) includes a spin chuck 56 for rotating a substrate W in asubstantially horizontal plane while holding the substrate W in asubstantially horizontal position under suction, a light irradiator 57for exposing the periphery of the substrate W held on the spin chuck 56to light, and the like. The pair of edge exposure units EEW1 and EEW2are arranged in vertically stacked relation in the center of theinterface block 5. The transport robot TR4 provided adjacent to the edgeexposure part EEW and the thermal processing tower 42 of the developmentprocessing block 4 is similar in construction to the above-mentionedtransport robots TR1 to TR3.

With reference to FIGS. 2 and 8, description will be further continued.FIG. 8 is a side view of the interface block 5 as seen from the (+X)side. A return buffer RBF for the return of substrates W is providedunder the pair of edge exposure units EEW1 and EEW2, and the pair ofvertically arranged substrate rest parts PASS9 and PASS10 are providedunder the return buffer RBF. The return buffer RBF is provided totemporarily store a substrate W subjected to a post-exposure bakeprocess in the heating parts PHP7 to PHP12 of the development processingblock 4 if the development processing block 4 is unable to perform thedevelopment process on the substrate W because of some sort ofmalfunction and the like. The return buffer RBF includes a cabinetcapable of storing a plurality of substrates W in tiers. The uppersubstrate rest part PASS9 is used for the transfer of a substrate W fromthe transport robot TR4 to the transport mechanism 55. The lowersubstrate rest part PASS10 is used for the transfer of a substrate Wfrom the transport mechanism 55 to the transport robot TR4. Thetransport robot TR4 gains access to the return buffer RBF.

As shown in FIG. 8, the transport mechanism 55 includes a movable base55 a in threaded engagement with a threaded shaft 522. The threadedshaft 522 is rotatably supported by a pair of support bases 523 so thatthe rotation axis thereof extends along the Y axis. The threaded shaft522 has one end coupled to a motor M1. The motor M1 drives the threadedshaft 522 to rotate, thereby moving the movable base 55 a horizontallyalong the Y axis.

A pair of holding arms 59 a and 59 b for holding a substrate W ismounted on the movable base 55 a so as to be arranged vertically. Thepair of holding arms 59 a and 59 b are movable upwardly and downwardly,pivotable, and movable back and forth in the direction of the pivotradius independently of each other by a drive mechanism incorporated inthe movable base 55 a. With such an arrangement, the transport mechanism55 transfers and receives a substrate W to and from the exposure unitEXP, transfers and receives a substrate W to and from the substrate restparts PASS9 and PASS10, and stores and takes a substrate W into and outof a send buffer SBF for the sending of substrates W. The send bufferSBF is provided to temporarily store a substrate W prior to the exposureprocess if the exposure unit EXP is unable to accept the substrate W,and includes a cabinet capable of storing a plurality of substrates W intiers.

As shown in FIGS. 2 and 8, the cleaning processing unit SOAK1 has anopening 58 on the (+X) side. Thus, the transport mechanism 55 cantransfer and receive a substrate W to and from the cleaning processingunit SOAK1 through the opening 58.

A downflow of clean air is always supplied into the indexer block 1, theBARC block 2, the resist coating block 3, the development processingblock 4, and the interface block 5 described above to thereby avoid theadverse effects of raised particles and gas flows upon the processes inthe respective blocks 1 to 5. Additionally, a slightly positive pressurerelative to the external environment of the substrate processingapparatus is maintained in each of the blocks 1 to 5 to prevent theentry of particles and contaminants from the external environment intothe blocks 1 to 5.

The indexer block 1, the BARC block 2, the resist coating block 3, thedevelopment processing block 4 and the interface block 5 as describedabove are units into which the substrate processing apparatus of thispreferred embodiment is divided in mechanical terms. The blocks 1 to 5are assembled to individual block frames, respectively, which are inturn connected together to construct the substrate processing apparatus.

On the other hand, this preferred embodiment employs another type ofunits, that is, transport control units regarding the transport ofsubstrates, aside from the blocks which are units based on theabove-mentioned mechanical division. The transport control unitsregarding the transport of substrates are referred to herein as “cells.”Each of the cells includes a transport robot responsible for thetransport of substrates, and a transport destination part to which thetransport robot transports a substrate. Each of the substrate rest partsdescribed above functions as an entrance substrate rest part for thereceipt of a substrate W into a cell or as an exit substrate rest partfor the transfer of a substrate W out of a cell. The transfer ofsubstrates W between the cells is also carried out through the substraterest parts. The transport robots constituting the cells include thesubstrate transfer mechanism 12 of the indexer block 1 and the transportmechanism 55 of the interface block 5.

The substrate processing apparatus in this preferred embodiment includessix cells: an indexer cell, a BARC cell, a resist coating cell, adevelopment processing cell, a post-exposure bake cell, and an interfacecell. The indexer cell includes the table 11 and the substrate transfermechanism 12, and is consequently similar in construction to the indexerblock 1 which is one of the units based on the mechanical division. TheBARC cell includes the bottom coating processor BRC, the pair of thermalprocessing towers 21 and the transport robot TR1. The BARC cell is alsoconsequently similar in construction to the BARC block 2 which is one ofthe units based on the mechanical division. The resist coating cellincludes the resist coating processor SC, the pair of thermal processingtowers 31, and the transport robot TR2. The resist coating cell is alsoconsequently similar in construction to the resist coating block 3 whichis one of the units based on the mechanical division.

The development processing cell includes the development processor SD,the thermal processing tower 41, and the transport robot TR3. Becausethe transport robot TR3 cannot gain access to the heating parts PHP7 toPHP12 and the cool plate CP14 of the thermal processing tower 42 asdiscussed above, the development processing cell does not include thethermal processing tower 42. Because the transport mechanism 55 of theinterface block 5 gains access to the cleaning processing unit SOAK1 ofthe cleaning processor SOAK, the cleaning processor SOAK is also notincluded in the development processing cell. In these respects, thedevelopment processing cell differs from the development processingblock 4 which is one of the units based on the mechanical division.

The post-exposure bake cell includes the thermal processing tower 42positioned in the development processing block 4, the edge exposure partEEW positioned in the interface block 5, and the transport robot TR4positioned in the interface block 5. That is, the post-exposure bakecell extends over the development processing block 4 and the interfaceblock 5 which are units based on the mechanical division. In thismanner, constituting one cell including the heating parts PHP7 to PHP12for performing the post-exposure bake process and the transport robotTR4 allows the rapid transport of exposed substrates W into the heatingparts PHP7 to PHP12 for the execution of the thermal process. Such anarrangement is preferred for the use of a chemically amplified resistwhich is required to be subjected to a heating process as soon aspossible after the exposure of a substrate W in a pattern.

The substrate rest parts PASS7 and PASS8 included in the thermalprocessing tower 42 are provided for the transfer of a substrate Wbetween the transport robot TR3 of the development processing cell andthe transport robot TR4 of the post-exposure bake cell.

The interface cell includes the transport mechanism 55 for transferringand receiving a substrate W to and from the exposure unit EXP which isan external apparatus, and the cleaning processor SOAK. The interfacecell has a construction different from that of the interface block 5which is one of the units based on the mechanical division in that theinterface cell includes the cleaning processor SOAK positioned in thedevelopment processing block 4 and does not include the transport robotTR4 and the edge exposure part EEW. The substrate rest parts PASS9 andPASS10 under the edge exposure part EEW are provided for the transfer ofa substrate W between the transport robot TR4 of the post-exposure bakecell and the transport mechanism 55 of the interface cell.

Next, a control mechanism in the substrate processing apparatus of thispreferred embodiment will be described. FIG. 9 is a schematic blockdiagram of the control mechanism. As shown in FIG. 9, the substrateprocessing apparatus of this preferred embodiment has a three-levelcontrol hierarchy composed of a main controller MC, cell controllers CC,and unit controllers. The main controller MC, the cell controllers CCand the unit controllers are similar in hardware construction to typicalcomputers. Specifically, each of the controllers includes a CPU forperforming various computation processes, a ROM or read-only memory forstoring a basic program therein, a RAM or readable/writable memory forstoring various pieces of information therein, a magnetic disk forstoring control applications and data therein, and the like.

The single main controller MC at the first level is provided for theentire substrate processing apparatus, and is principally responsiblefor the management of the entire substrate processing apparatus, themanagement of a main panel MP, and the management of the cellcontrollers CC. The main panel MP functions as a display for the maincontroller MC. Various commands and parameters may be entered into themain controller MC from a keyboard KB. The main panel MP may be in theform of a touch panel so that a user performs an input process into themain controller MC from the main panel MP.

The cell controllers CC at the second level are individually provided incorresponding relation to the six cells (the indexer cell, the BARCcell, the resist coating cell, the development processing cell, thepost-exposure bake cell, and the interface cell). Each of the cellcontrollers CC is principally responsible for the control of thetransport of substrates and the management of the units in acorresponding cell. Specifically, the cell controllers CC for therespective cells send and receive information in such a manner that afirst cell controller CC for a first cell sends information indicatingthat a substrate W is placed on a predetermined substrate rest part to asecond cell controller CC for a second cell adjacent to the first cell,and the second cell controller CC for the second cell having receivedthe substrate W sends information indicating that the substrate W isreceived from the predetermined substrate rest part back to the firstcell controller CC. Such sending and receipt of information are carriedout through the main controller MC. Each of the cell controllers CCprovides the information indicating that a substrate W is transportedinto a corresponding cell to a transport robot controller TC, which inturn controls a corresponding transport robot to circulatingly transportthe substrate W in the corresponding cell in accordance with apredetermined procedure. The transport robot controller TC is acontroller implemented by the operation of a predetermined applicationin the corresponding cell controller CC.

Examples of the unit controllers at the third level include a spincontroller and a bake controller. The spin controller directly controlsthe spin units (the coating processing units, the development processingunits and the cleaning processing unit) provided in a corresponding cellin accordance with an instruction given from a corresponding cellcontroller CC. Specifically, the spin controller controls, for example,a spin motor for a spin unit to adjust the number of revolutions of asubstrate W. The bake controller directly controls the thermalprocessing units (the hot plates, the cool plates, the heating parts,and the like) provided in a corresponding cell in accordance with aninstruction given from a corresponding cell controller CC. Specifically,the bake controller controls, for example, a heater incorporated in ahot plate to adjust a plate temperature and the like.

The host computer 100 connected via the LAN lines to the substrateprocessing apparatus ranks as a higher level control mechanism than thethree-level control hierarchy provided in the substrate processingapparatus (See FIG. 1). The host computer 100 includes a CPU forperforming various computation processes, a ROM or read-only memory forstoring a basic program therein, a RAM or readable/writable memory forstoring various pieces of information therein, a magnetic disk forstoring control applications and data therein, and the like. The hostcomputer 100 is similar in construction to a typical computer.Typically, a plurality of substrate processing apparatuses according tothis preferred embodiment are connected to the host computer 100. Thehost computer 100 provides a recipe containing descriptions about aprocessing procedure and processing conditions to each of the substrateprocessing apparatuses connected thereto. The recipe provided from thehost computer 100 is stored in a storage part (e.g., a memory) of themain controller MC of each of the substrate processing apparatuses.

The exposure unit EXP is provided with a separate controller independentof the above-mentioned control mechanism of the substrate processingapparatus. In other words, the exposure unit EXP does not operate underthe control of the main controller MC of the substrate processingapparatus, but controls its own operation alone. Such an exposure unitEXP also controls its own operation in accordance with a recipe receivedfrom the host computer 100.

Next, the operation of the substrate processing apparatus of thispreferred embodiment will be described. First, description will be givenon a general procedure for the circulating transport of substrates W inthe substrate processing apparatus. The processing procedure to bedescribed below is in accordance with the descriptions of the recipereceived from the host computer 100.

First, unprocessed substrates W stored in a cassette C are transportedfrom the outside of the substrate processing apparatus into the indexerblock 1 by an AGV (automatic guided vehicle) and the like. Subsequently,the unprocessed substrates W are transferred outwardly from the indexerblock 1. Specifically, the substrate transfer mechanism 12 in theindexer cell (or the indexer block 1) takes an unprocessed substrate Wout of a predetermined cassette C, and places the unprocessed substrateW onto the substrate rest part PASS1. After the unprocessed substrate Wis placed on the substrate rest part PASS 1, the transport robot TR1 ofthe BARC cell uses one of the holding arms 6 a and 6 b to receive theunprocessed substrate W. The transport robot TR1 transports the receivedunprocessed substrate W to one of the coating processing units BRC1 toBRC3. In the coating processing units BRC1 to BRC3, the substrate W isspin-coated with the coating solution for the anti-reflective film.

After the completion of the coating process, the transport robot TR1transports the substrate W to one of the hot plates HP1 to HP6. Heatingthe substrate W in the hot plate dries the coating solution to form theanti-reflective film serving as the undercoat on the substrate W.Thereafter, the transport robot TR1 takes the substrate W from the hotplate, and transports the substrate W to one of the cool plates CP1 toCP3, which in turn cools down the substrate W. In this step, one of thecool plates WCP may be used to cool down the substrate W. The transportrobot TR1 places the cooled substrate W onto the substrate rest partPASS3.

Alternatively, the transport robot TR1 may be adapted to transport theunprocessed substrate W placed on the substrate rest part PASS1 to oneof the adhesion promotion processing parts AHL1 to AHL3. In the adhesionpromotion processing parts AHL1 to AHL3, the substrate W is thermallyprocessed in a vapor atmosphere of HMDS, whereby the adhesion of theresist film to the substrate W is promoted. The transport robot TR1takes out the substrate W subjected to the adhesion promotion process,and transports the substrate W to one of the cool plates CP1 to CP3,which in turn cools down the substrate W. Because no anti-reflectivefilm is to be formed on the substrate W subjected to the adhesionpromotion process, the cooled substrate W is directly placed onto thesubstrate rest part PASS3 by the transport robot TR1.

A dehydration process may be performed prior to the application of thecoating solution for the anti-reflective film. In this case, thetransport robot TR1 transports the unprocessed substrate W placed on thesubstrate rest part PASS1 first to one of the adhesion promotionprocessing parts AHL1 to AHL3. In the adhesion promotion processingparts AHL1 to AHL3, a heating process (dehydration bake) merely fordehydration is performed on the substrate W without supplying the vaporatmosphere of HMDS. The transport robot TR1 takes out the substrate Wsubjected to the heating process for dehydration, and transports thesubstrate W to one of the cool plates CP1 to CP3, which in turn coolsdown the substrate W. The transport robot TR1 transports the cooledsubstrate W to one of the coating processing units BRC1 to BRC3. In thecoating processing units BRC1 to BRC3, the substrate W is spin-coatedwith the coating solution for the anti-reflective film. Thereafter, thetransport robot TR1 transports the substrate W to one of the hot platesHP1 to HP6. Heating the substrate W in the hot plate forms theanti-reflective film serving as the undercoat on the substrate W.Thereafter, the transport robot TR1 takes the substrate W from the hotplate, and transports the substrate W to one of the cool plates CP1 toCP3, which in turn cools down the substrate W. Then, the transport robotTR1 places the cooled substrate W onto the substrate rest part PASS3.

After the substrate W is placed on the substrate rest part PASS3, thetransport robot TR2 in the resist coating cell receives the substrate W,and transports the substrate W to one of the coating processing unitsSC1 to SC3. In the coating processing units SC1 to SC3, the substrate Wis spin-coated with the resist. Because the resist coating processrequires precise substrate temperature control, the substrate W may betransported to one of the cool plates CP4 to CP9 immediately beforebeing transported to the coating processing units SC1 to SC3.

After the completion of the resist coating process, the transport robotTR2 transports the substrate W to one of the heating parts PHP1 to PHP6.In the heating parts PHP1 to PHP6, heating the substrate W removes asolvent component from the resist to form a resist film on the substrateW. Thereafter, the transport robot TR2 takes the substrate W from theone of the heating parts PHP1 to PHP6, and transports the substrate W toone of the cool plates CP4 to CP9, which in turn cools down thesubstrate W. Then, the transport robot TR2 places the cooled substrate Wonto the substrate rest part PASS5.

After the substrate W with the resist film formed thereon by the resistcoating process is placed on the substrate rest part PASS5, thetransport robot TR3 in the development processing cell receives thesubstrate W, and places the substrate W onto the substrate rest partPASS7 without any processing of the substrate W. Then, the transportrobot TR4 in the post-exposure bake cell receives the substrate W placedon the substrate rest part PASS7, and transports the substrate W to oneof the edge exposure units EEW1 and EEW2. In the edge exposure unitsEEW1 and EEW2, a peripheral edge portion of the substrate W is exposedto light. The transport robot TR4 places the substrate W subjected tothe edge exposure process onto the substrate rest part PASS9. Thetransport mechanism 55 in the interface cell receives the substrate Wplaced on the substrate rest part PASS9, and transports the substrate Winto the exposure unit EXP. The substrate W transported into theexposure unit EXP is subjected to the pattern exposure process. In thisstep, the transport mechanism 55 uses the holding arm 59 a to transportthe substrate W from the substrate rest part PASS9 to the exposure unitEXP.

Because the chemically amplified resist is used in this preferredembodiment, an acid is formed by a photochemical reaction in the exposedportion of the resist film formed on the substrate W. In the exposureunit EXP, the substrate W is subjected to an immersion exposure process.The immersion exposure process refers to a technique for immersing asubstrate W in a liquid with a high refractive index (e.g., deionizedwater with a refractive index of 1.44) to expose the substrate W in apattern, and can achieve a high resolution with virtually no change ofthe conventional light source and exposure process. The substrate Wsubjected to the edge exposure process may be transported to the coolplate CP14 for the cooling process by the transport robot TR4 beforebeing transported to the exposure unit EXP.

The exposed substrate W subjected to the pattern exposure process istransported from the exposure unit EXP back to the interface cell again.The transport mechanism 55 transports the exposed substrate W into thecleaning processing unit SOAK1. In this step, the transport mechanism 55uses the holding arm 59 b to transport the substrate W from the exposureunit EXP to the cleaning processing unit SOAK1. There are cases where aliquid adheres to the substrate W subjected to the immersion exposureprocess. However, the holding arm 59 a is used for the transport of thesubstrate W prior to the exposure and the holding arm 59 b isexclusively used for the transport of the substrate W after theexposure. This avoids the adhesion of the liquid to at least the holdingarm 59 a, to prevent the transfer of the liquid to the substrate W priorto the exposure.

A processing operation in the cleaning processing unit SOAK1 will bedescribed. First, when a substrate W is transported into the cleaningprocessing unit SOAK1, the splash guard 424 is moved downwardly, and thetransport mechanism 55 places the substrate W onto the spin chuck 421.The substrate W placed on the spin chuck 421 is held in a horizontalposition under suction by the spin chuck 421.

Next, the splash guard 424 moves to the above-mentioned drainageposition, and the cleaning processing nozzle 450 moves to over thecenter of the substrate W. Thereafter, the rotary shaft 425 startsrotating. As the rotary shaft 425 rotates, the substrate W held by thespin chuck 421 is rotated. Thereafter, the valve Va is opened to applythe cleaning liquid from the cleaning processing nozzle 450 onto theupper surface of the substrate W. In this preferred embodiment,deionized water is applied as the cleaning liquid onto the substrate W.Thus, the cleaning process of the substrate W proceeds to wash away theliquid for immersion exposure from the substrate W. The liquid splashedfrom the rotating substrate W by centrifugal force is guided by thedrainage guide groove 441 into the drainage space 431, and is drainedthrough the drainage pipe 434. In this preferred embodiment, because thedeionized water is used as the cleaning liquid, an additional rinsingliquid is not supplied. In place of the valve Va, the valve Vb may beopened to discharge deionized water as the rinsing liquid from thecleaning processing nozzle 450.

After a lapse of a predetermined time period, the speed of rotation ofthe rotary shaft 425 decreases. This decreases the amount of deionizedwater serving as the cleaning liquid spattered by the rotation of thesubstrate W to form a film of water on the entire surface of thesubstrate W in such a manner that a puddle of water remains on thesubstrate W. Alternatively, a film of water may be formed on the entiresurface of the substrate W by stopping the rotation of the rotary shaft425.

Next, the supply of the cleaning liquid is stopped. The cleaningprocessing nozzle 450 is retracted to a predetermined position, and thedrying processing nozzle 451 moves to over the center of the substrateW. Thereafter, the valve Vc is opened to apply an inert gas (in thispreferred embodiment, nitrogen gas) from the drying processing nozzle451 to near the center of the upper surface of the substrate W. Thus,the water or moisture in the center of the substrate W is forced towardthe peripheral edge portion of the substrate W. As a result, the film ofwater remains only in the peripheral edge portion of the substrate W.

Next, the speed of rotation of the rotary shaft 425 increases again, andthe drying processing nozzle 451 gradually moves from over the center ofthe substrate W toward over the peripheral edge portion of the substrateW. Thus, a great centrifugal force is exerted on the film of waterremaining on the substrate W, and the inert gas can impinge on theentire surface of the substrate W, whereby the film of water on thesubstrate W is reliably removed. As a result, the substrate W is driedwith reliability.

Next, the supply of the inert gas is stopped. The drying processingnozzle 451 is retracted to a predetermined position, and the rotation ofthe rotary shaft 425 is stopped. Thereafter, the splash guard 424 ismoved downwardly, and the transport mechanism 55 transports thesubstrate W out of the cleaning processing unit SOAK1. This completesthe processing operation in the cleaning processing unit SOAK1. Theposition of the splash guard 424 during the cleaning and dryingprocesses is preferably appropriately changed depending on the need forthe collection and drainage of the processing liquid.

The substrate W subjected to the cleaning and drying processes in thecleaning processing unit SOAK1 is placed on the substrate rest partPASS10 by the transport mechanism 55. In this step, the transportmechanism 55 uses the holding arm 59 a to transport the substrate W fromthe cleaning processing unit SOAK1 to the substrate rest part PASS10.After the exposed substrate W is placed on the substrate rest partPASS10, the transport robot TR4 in the post-exposure bake cell receivesthe substrate W, and transports the substrate W to one of the heatingparts PHP7 to PHP12. The processing operation in the heating parts PHP7to PHP12 is as described above. In the heating parts PHP7 to PHP12, theheating process (or the post-exposure bake process) is performed whichcauses a reaction such as crosslinking, polymerization and the like ofthe resist resin to proceed by using a product formed by thephotochemical reaction during the exposure process as an acid catalyst,thereby locally changing the solubility of only an exposed portion ofthe resist resin in the developing solution. The local transportmechanism 720 having the cooling mechanism transports the substrate Wsubjected to the post-exposure bake process to thereby cool down thesubstrate W, whereby the above-mentioned chemical reaction stops.Subsequently, the transport robot TR4 takes the substrate W from the oneof the heating parts PHP7 to PHP12, and places the substrate W onto thesubstrate rest part PASS8. The procedure from the end of exposure in theexposure unit EXP to the start of the post-exposure bake process in theheating parts PHP7 to PHP12 will be described later.

After the substrate W is placed on the substrate rest part PASS8, thetransport robot TR3 in the development processing cell receives thesubstrate W, and transports the substrate W to one of the cool platesCP10 to CP13. In the cool plates CP10 to CP13, the substrate W subjectedto the post-exposure bake process is further cooled down and preciselycontrolled at a predetermined temperature. Thereafter, the transportrobot TR3 takes the substrate W from the one of the cool plates CP10 toCP13, and transports the substrate W to one of the developmentprocessing units SD1 to SD4. In the development processing units SD1 toSD4, the developing solution is applied onto the substrate W to causethe development process to proceed. After the completion of thedevelopment process, the transport robot TR3 transports the substrate Wto one of the hot plates HP7 to HP11, and then transports the substrateW to one of the cool plates CP10 to CP13.

Thereafter, the transport robot TR3 places the substrate W onto thesubstrate rest part PASS6. The transport robot TR2 in the resist coatingcell places the substrate W from the substrate rest part PASS6 onto thesubstrate rest part PASS4 without any processing of the substrate W.Next, the transport robot TR1 in the BARC cell places the substrate Wfrom the substrate rest part PASS4 onto the substrate rest part PASS2without any processing of the substrate W, whereby the substrate W isstored in the indexer block 1. Then, the substrate transfer mechanism 12in the indexer cell stores the processed substrate W held on thesubstrate rest part PASS2 into a predetermined cassette C. Thereafter,the cassette C in which a predetermined number of processed substrates Ware stored is transported to the outside of the substrate processingapparatus. Thus, a series of photolithography processes are completed.

In the substrate processing apparatus according to this preferredembodiment, the chemically amplified resist is applied as thephotoresist to the substrate W. When the chemically amplified resist isused, a slight variation in processing conditions exerts a largeinfluence upon line width uniformity, as described above. For thisreason, processing conditions are made as constant as possible for allof the substrates W to be processed. In particular, the substrateprocessing apparatus according to this preferred embodiment is managedso as to provide a constant time interval between the instant of thecompletion of the exposure process in the exposure unit EXP and theinstant of the start of the post-exposure bake process in the heatingparts PHP7 to PHP12, because this time interval exerts the greatestinfluence on the line width uniformity.

Additionally, the substrate processing apparatus according to thispreferred embodiment is adapted to provide a constant time intervalbetween the instant of the completion of the cleaning process ofsubstrates W in the cleaning processing unit SOAK1 and the instant ofthe start of the post-exposure bake process of the substrates W in theheating parts PHP7 to PHP12. This preferred embodiment adopts atechnique to be described below to provide the constant time intervalbetween the instant of the completion of the exposure process in theexposure unit EXP and the instant of the start of the post-exposure bakeprocess in the heating parts PHP7 to PHP12 and to provide the constanttime interval between the instant of the completion of the cleaningprocess in the cleaning processing unit SOAK1 and the instant of thestart of the post-exposure bake process in the heating parts PHP7 toPHP12.

FIG. 10 is a flow chart showing a processing procedure from the end ofthe exposure in the exposure unit EXP to the start of the post-exposurebake process in the heating parts PHP7 to PHP12. FIG. 11 is a timingchart for processing from the end of the exposure to the post-exposurebake process. First, the exposure process of a substrate W in theexposure unit EXP is completed at time t1 (in Step S1). At this point,the exposure unit EXP sends an exposure completion signal, and thesubstrate processing apparatus receives the exposure completion signalthrough the host computer 100. As a result, the main controller MC ofthe substrate processing apparatus recognizes the completion of theexposure process of the substrate W in the exposure unit EXP at the timet1 to store the time t1 as an exposure completion time in a storageportion thereof.

Subsequently, the substrate W subjected to the exposure process isreturned from the exposure unit EXP to the interface cell (in Step S2),and is transported into the cleaning processing unit SOAK1 by thetransport mechanism 55 (in Step S3). The procedure of the processes inStep S3 and its subsequent steps is executed by the cell controllers CCfor the interface cell and the post-exposure bake cell controlling themechanical parts in accordance with an instruction from the maincontroller MC. A basic flow of the cleaning and drying processes of asubstrate W in the cleaning processing unit SOAK1 is as discussed above.

In a pattern labeled (a) in FIG. 11, it takes a relatively long time totransport a substrate W from the exposure unit EXP to the cleaningprocessing unit SOAK1, and the substrate W subjected to the exposureprocess is transported into the cleaning processing unit SOAK1 at timet3. The relatively long time required for the substrate W subjected tothe exposure process to be transported into the cleaning processing unitSOAK1 can result from a factor such that the transport mechanism 55 isperforming a wafer feed operation (or the operation of transferring anunexposed substrate W to the exposure unit EXP) at the time of thetransfer of the substrate W subjected to the exposure process from theexposure unit EXP to the transport mechanism 55.

After the substrate W is transported into the cleaning processing unitSOAK1 at the time t3, the substrate W waits until time t4 in thecleaning processing unit SOAK1 (in Step S4). Specifically, the substrateW waits while being held by the spin chuck 421 under suction without theapplication of the cleaning liquid thereto from the cleaning processingnozzle 450. At the time t4, the application of the cleaning liquid fromthe cleaning processing nozzle 450 starts while the substrate W isrotated. Thus, the cleaning process of the substrate W is executed (inStep S5). Next, the application of the inert gas to near the center ofthe upper surface of the substrate W from the drying processing nozzle451 starts at time t5. The cleaning process of the substrate W in thecleaning processing unit SOAK1 is completed at the time t5. After thetime t5, the drying process of the substrate W is executed (in Step S6).Thereafter, the supply of the inert gas from the drying processingnozzle 451 is stopped at time t6, and the drying process of thesubstrate W is completed. Thereafter, the substrate W transported out ofthe cleaning processing unit SOAK1 by the transport mechanism 55 istransported into one of the heating parts PHP7 to PHP12 by the transportmechanism 55 and the transport robot TR4 (in Step S7). The post-exposurebake process of the substrate W in the one of the heating parts PHP7 toPHP12 (in Step S8) starts at time t7.

In a pattern labeled (b) in FIG. 11, it takes a relatively short time totransport a substrate W from the exposure unit EXP to the cleaningprocessing unit SOAK1, and the substrate W subjected to the exposureprocess is transported into the cleaning processing unit SOAK1 at timet2. If the transport mechanism 55 is able to receive the exposedsubstrate W immediately after the substrate W is fed out of the exposureunit EXP, the substrate W is transported to the cleaning processing unitSOAK1 for such a short time.

After the substrate W is transported into the cleaning processing unitSOAK1 at the time t2, the substrate W waits until the time t4 in thecleaning processing unit SOAK1. Subsequently, the application of thecleaning liquid from the cleaning processing nozzle 450 starts while thesubstrate W is rotated at the time t4, and the application of the inertgas to near the center of the upper surface of the substrate W from thedrying processing nozzle 451 starts at the time t5, in a manner similarto that in the above-mentioned pattern labeled (a). The supply of theinert gas from the drying processing nozzle 451 is stopped at the timet6. The substrate W is transported from the cleaning processing unitSOAK1 to one of the heating parts PHP7 to PHP12. The post-exposure bakeprocess of the substrate W starts at the time t7.

As discussed above, the substrate processing apparatus and the exposureunit EXP have the individual control mechanisms, respectively, and theoperations thereof are not completely synchronized. Thus, there arecases where the transport mechanism 55 is unable to receive a substrateW subjected to the exposure process at the time of the feed of thesubstrate W from the exposure unit EXP, and variations sometimes arisein a transport time interval between the completion of the exposureprocess and the transport of the substrate W into the cleaningprocessing unit SOAK1 (See (a) and (b) in FIG. 11). If the subsequentcleaning and drying processes are executed and the post-exposure bakeprocess is started in the presence of such variations, uneven timeintervals occur between the instant of the completion of the exposureprocess and the instant of the start of the post-exposure bake process.Even if an adjustment is made to the time at which the post-exposurebake process starts to provide a constant time interval between theinstant of the completion of the exposure process and the instant of thestart of the post-exposure bake process, uneven time intervals resultbetween the instant of the completion of the cleaning process in thecleaning processing unit SOAK1 and the instant of the start of thepost-exposure bake process.

Thus, the main controller MC adjusts the waiting time of the exposedsubstrate W transported into the cleaning processing unit SOAK1 so as toprovide a constant time interval between the exposure process completiontime t1 and the time t5 at which the cleaning process is completed,thereby to provide the constant time interval between the instant (thetime t1) of the completion of the exposure process in the exposure unitEXP and the instant (the time t7) of the start of the post-exposure bakeprocess in the heating parts PHP7 to PHP12 and to provide the constanttime interval between the instant (the time t5) of the completion of thecleaning process in the cleaning processing unit SOAK1 and the instant(the time t7) of the start of the post-exposure bake process in theheating parts PHP7 to PHP12. The cleaning and drying processes in thecleaning processing unit SOAK1 and the subsequent substrate transportare executed in accordance with a previously set predetermined sequence,and are each carried out for a constant time period. Therefore, theadjustment made to the waiting time of the exposed substrate W in thecleaning processing unit SOAK1 to provide a constant time intervalbetween the exposure process completion time t1 and the cleaning processstart time t4 achieves the constant time interval between the exposureprocess completion time and the post-exposure bake process start timeand the constant time interval between the cleaning process completiontime and the post-exposure bake process start time.

In place of the adjustment made to the waiting time of the exposedsubstrate W in the cleaning processing unit SOAK1, an adjustment may bemade to the cleaning processing time to provide the constant timeinterval between the exposure process completion time t1 and thecleaning process completion time t5. In a pattern labeled (c) in FIG.11, it takes a relatively short time to transport a substrate W from theexposure unit EXP to the cleaning processing unit SOAK1, and thesubstrate W subjected to the exposure process is transported into thecleaning processing unit SOAK1 at the time t2 in a manner similar tothat in the pattern labeled (b). Subsequently, the application of thecleaning liquid from the cleaning processing nozzle 450 starts while thesubstrate W is rotated at the time t2 without any particular waitingstep, and the application of the inert gas to near the center of theupper surface of the substrate W from the drying processing nozzle 451starts at the time t5. Thereafter, in a manner similar to those in thepatterns labeled (a) and (b), the supply of the inert gas from thedrying processing nozzle 451 is stopped at the time t6, and thesubstrate W is transported from the cleaning processing unit SOAK1 toone of the heating parts PHP7 to PHP12. Also, the post-exposure bakeprocess of the substrate W starts at the time t7.

In this manner, the main controller MC may adjust the cleaning time ofthe exposed substrate W transported into the cleaning processing unitSOAK1 so as to provide the constant time interval between the exposureprocess completion time t1 and the cleaning process completion time t5.This also provides the constant time interval between the instant (thetime t1) of the completion of the exposure process in the exposure unitEXP and the instant (the time t7) of the start of the post-exposure bakeprocess in the heating parts PHP7 to PHP12, and provides the constanttime interval between the instant (the time t5) of the completion of thecleaning process in the cleaning processing unit SOAK1 and the instant(the time t7) of the start of the post-exposure bake process in theheating parts PHP7 to PHP12.

A summary of the details of the patterns labeled (a) to (c) in FIG. 11is as follows. The cell controller CC of the interface cell controls themechanical parts in accordance with an instruction from the maincontroller MC to adjust the length of time (referred to hereinafter as a“presence time”) that the exposed substrate W is present in the cleaningprocessing unit SOAK1, thereby adjusting the instant of the end of thecleaning process so as to provide the constant time interval between theinstant of the completion of the exposure process and the instant of theend of the cleaning process. This provides the constant time intervalbetween the instant of the completion of the exposure process and theinstant of the start of the post-exposure bake process, and provides theconstant time interval between the instant of the completion of thecleaning process and the instant of the start of the post-exposure bakeprocess. The constant time interval between the instant of thecompletion of the exposure process and the instant of the start of thepost-exposure bake process and the constant time interval between theinstant of the completion of the cleaning process and the instant of thestart of the post-exposure bake process achieve further improvements inthe line width uniformity of a pattern formed when the chemicallyamplified resist is used. The adjustment made to the presence time ofthe exposed substrate W in the cleaning processing unit SOAK1 avoids theinfluence of heat upon the exposed substrate W more reliably than theadjustment made to the waiting time of the substrate W in the heatingparts PHP7 to PHP12. In the pattern labeled (c) in FIG. 11, the exposedsubstrate W is in contact with the water for a relatively long time.However, whether this cleaning time is long or short is considered tohave little effect on the line width uniformity of a pattern.

While the preferred embodiment according to the present invention isdescribed hereinabove, the present invention is not limited to theabove-mentioned specific embodiment. For example, the above-mentionedpreferred embodiment is based on the premise that each of the cleaningand drying processes in the cleaning processing unit SOAK1 and thesubsequent substrate transport requires an approximately constant time.If variations arise in the time required for these processes, amodification may be made to cause the substrate W to further wait in theheating parts PHP7 to PHP12, thereby providing the constant timeinterval between the instant of the completion of the exposure processand the instant of the start of the post-exposure bake process and theconstant time interval between the instant of the completion of thecleaning process and the instant of the start of the post-exposure bakeprocess. For example, if variations arise in the time required for thesubstrate transport from the cleaning processing unit SOAK1 to theheating parts PHP7 to PHP12, such a modification is made to cause thesubstrate W to wait in the temporary substrate rest part 719 of theheating parts PHP7 to PHP12, thereby adjusting the time interval betweenthe instant of the completion of the cleaning process and the instant ofthe start of the post-exposure bake process to be constant. In otherwords, when the instant of the end of the cleaning process is adjustedso that the time interval between the instant of the completion of theexposure process and the instant of the end of the cleaning process isconstant, subsequently adjusting the time interval between the instantof the completion of the cleaning process and the instant of the startof the post-exposure bake process in the heating parts PHP7 to PHP12 tobe constant leads to adjusting the time interval between the instant ofthe completion of the exposure process and the instant of the start ofthe post-exposure bake process to be constant.

The drying process as a step subsequent to the cleaning process in thecleaning processing unit SOAK1 is not essential.

The construction of the substrate processing apparatus according to thepresent invention is not limited to the configuration shown in FIGS. 1to 4. However, various modifications may be made to the construction ofthe substrate processing apparatus if a transport robot circulatinglytransports a substrate W to a plurality of processing parts wherebypredetermined processes are performed on the substrate W.

While the invention has been described in detail, the foregoingdescription is in all aspects illustrative and not restrictive. It isunderstood that numerous other modifications and variations can bedevised without departing from the scope of the invention.

1. A substrate processing apparatus disposed adjacent to an exposureapparatus, said substrate processing apparatus comprising: a cleaningprocessing part for performing at least a cleaning process on asubstrate subjected to an exposure process by said exposure apparatus; aheating processing part for performing a heating process on a substratesubjected to said cleaning process; a transport mechanism for receivinga substrate from said exposure apparatus to transport the substratethrough said cleaning processing part to said heating processing part;and a controller for providing an approximately constant firstinterprocess time interval between the instant at which said exposureapparatus completes the exposure process of a substrate and the instantat which said heating processing part starts the heating process of thesubstrate, and for providing an approximately constant secondinterprocess time interval between the instant at which said cleaningprocessing part completes the cleaning process of the substrate and theinstant at which said heating processing part starts the heating processof the substrate.
 2. The substrate processing apparatus according toclaim 1, wherein said controller adjusts the instant at which saidcleaning processing part completes the cleaning process to therebyprovide the approximately constant first interprocess time interval andthe approximately constant second interprocess time interval.
 3. Thesubstrate processing apparatus according to claim 2, wherein saidcontroller adjusts a presence time for which the substrate subjected tothe exposure process is present in the cleaning processing part tothereby adjust said instant at which said cleaning processing partcompletes the cleaning process.
 4. The substrate processing apparatusaccording to claim 3, wherein said controller adjusts a waiting time forwhich the substrate subjected to the exposure process and transported tosaid cleaning processing part waits until said cleaning process tothereby adjust said presence time.
 5. The substrate processing apparatusaccording to claim 3, wherein said controller adjusts a cleaningprocessing time for which the substrate subjected to the exposureprocess is subjected to the cleaning process by said cleaning processingpart to thereby adjust said presence time.
 6. The substrate processingapparatus according to claim 1, wherein said exposure apparatus performsan immersion exposure process on a substrate.
 7. A method of processinga substrate subjected to an exposure process, said method comprising thesteps of: transporting a substrate subjected to the exposure process toa cleaning processing part; performing a cleaning process in saidcleaning processing part on said substrate subjected to the exposureprocess; transporting said substrate subjected to the cleaning processfrom said cleaning processing part to a heating processing part; andperforming a heating process in said heating processing part on saidsubstrate subjected to the cleaning process, wherein a firstinterprocess time interval between the instant at which the exposureprocess of a substrate is completed and the instant at which the heatingprocess of the substrate is started is made approximately constant, anda second interprocess time interval between the instant at which thecleaning process of the substrate is completed and the instant at whichthe heating process of the substrate is started is made approximatelyconstant.
 8. The method according to claim 7, wherein said firstinterprocess time interval and said second interprocess time intervalare made approximately constant by adjusting the instant at which saidcleaning processing part completes the cleaning process.
 9. The methodaccording to claim 8, wherein said instant at which said cleaningprocessing part completes the cleaning process is adjusted by adjustinga presence time for which the substrate subjected to the exposureprocess is present in said cleaning processing part.
 10. The methodaccording to claim 9, wherein said presence time is adjusted byadjusting a waiting time for which the substrate subjected to theexposure process and transported to said cleaning processing part waitsuntil said cleaning process.
 11. The method according to claim 9,wherein said presence time is adjusted by adjusting a cleaningprocessing time for which the substrate subjected to the exposureprocess is subjected to the cleaning process by said cleaning processingpart.
 12. The method according to claim 7, wherein said exposure processis an immersion exposure process.